I am standing next to a five-year old girl in pormpuraaw, a small Aboriginal community on the western edge of Cape York in northern Australia. When I ask her to point north, she points precisely and without hesitation. My compass says she is right. Later, back in a lecture hall at Stanford University, I make the same request of an audience of distinguished scholars—winners of science medals and genius prizes. Some of them have come to this very room to hear lectures for more than 40 years. I ask them to close their eyes (so they don’t cheat) and point north. Many refuse; they do not know the answer. Those who do point take a while to think about it and then aim in all possible directions. I have repeated this exercise at Harvard and Princeton and in Moscow, London and Beijing, always with the same results.

A five-year-old in one culture can do something with ease that eminent scientists in other cultures struggle with. This is a big difference in cognitive ability. What could explain it? The surprising answer, it turns out, may be language.